Fix text wrapping and eliding with implicitWidth.

Update the implicitWidth of the item before continuing with the layout
rather than after it's completed this gives any bindings dependent on
the implicitWidth the opportunity to update the width before the layout
continues.

Task-number: QTBUG-22680
Task-number: QTBUG-24251
Change-Id: I61cd96ad9891b22d8b83937ad2c06719f88976b6
Reviewed-by: Martin Jones <martin.jones@nokia.com>

5 files changed, 112 insertions, 20 deletions

diff --git a/src/quick/items/qquicktext.cpp b/src/quick/items/qquicktext.cpp
index 9f22dfdd08..d7303352c5 100644
--- a/src/quick/items/qquicktext.cpp
+++ b/src/quick/items/qquicktext.cpp
@@ -421,6 +421,10 @@ void QQuickTextPrivate::updateSize()
     //setup instance of QTextLayout for all cases other than richtext
     if (!richText) {
         QRectF textRect = setupTextLayout(&naturalWidth);
+
+        if (internalWidthUpdate)    // probably the result of a binding loop, but by letting it
+            return;      // get this far we'll get a warning to that effect if it is.
+
         layedOutTextRect = textRect;
         size = textRect.size();
         dy -= size.height();
@@ -443,7 +447,13 @@ void QQuickTextPrivate::updateSize()
         if (requireImplicitWidth && q->widthValid()) {
             extra->doc->setTextWidth(-1);
             naturalWidth = extra->doc->idealWidth();
+            const bool wasInLayout = internalWidthUpdate;
+            internalWidthUpdate = true;
+            q->setImplicitWidth(naturalWidth);
+            internalWidthUpdate = wasInLayout;
         }
+        if (internalWidthUpdate)
+            return;
         if (wrapMode != QQuickText::NoWrap && q->widthValid())
             extra->doc->setTextWidth(q->width());
         else
@@ -468,8 +478,6 @@ void QQuickTextPrivate::updateSize()
     qreal iWidth = -1;
     if (!q->widthValid())
         iWidth = size.width();
-    else if (requireImplicitWidth)
-        iWidth = naturalWidth;
     if (iWidth > -1)
         q->setImplicitSize(iWidth, size.height());
     internalWidthUpdate = false;
@@ -697,6 +705,11 @@ QRectF QQuickTextPrivate::setupTextLayout(qreal *const naturalWidth)
             layout.endLayout();
             *naturalWidth = layout.maximumWidth();
             layout.clearLayout();
+
+            bool wasInLayout = internalWidthUpdate;
+            internalWidthUpdate = true;
+            q->setImplicitWidth(*naturalWidth);
+            internalWidthUpdate = wasInLayout;
         }
 
         QFontMetrics fm(font);
@@ -704,7 +717,7 @@ QRectF QQuickTextPrivate::setupTextLayout(qreal *const naturalWidth)
         return QRect(0, 0, 0, height);
     }
 
-    const qreal lineWidth = q->widthValid() ? q->width() : FLT_MAX;
+    qreal lineWidth = q->widthValid() && q->width() > 0 ? q->width() : FLT_MAX;
     const qreal maxHeight = q->heightValid() ? q->height() : FLT_MAX;
 
     const bool customLayout = isLineLaidOutConnected();
@@ -735,6 +748,7 @@ QRectF QQuickTextPrivate::setupTextLayout(qreal *const naturalWidth)
     QTextLine line;
     int visibleCount = 0;
     bool elide;
+    bool widthChanged;
     qreal height = 0;
     QString elideText;
     bool once = true;
@@ -755,13 +769,14 @@ QRectF QQuickTextPrivate::setupTextLayout(qreal *const naturalWidth)
                 scaledFont.setPointSize(scaledFontSize);
             layout.setFont(scaledFont);
         }
-        layout.beginLayout();
 
+        layout.beginLayout();
 
         bool wrapped = false;
         bool truncateHeight = false;
         truncated = false;
         elide = false;
+        widthChanged = false;
         int characterCount = 0;
         int unwrappedLineCount = 1;
         int maxLineCount = maximumLineCount();
@@ -864,7 +879,6 @@ QRectF QQuickTextPrivate::setupTextLayout(qreal *const naturalWidth)
             br = br.united(line.naturalTextRect());
             line = nextLine;
         }
-
         layout.endLayout();
         br.moveTop(0);
 
@@ -886,8 +900,21 @@ QRectF QQuickTextPrivate::setupTextLayout(qreal *const naturalWidth)
                     if (!line.isValid())
                         break;
                 }
+
                 *naturalWidth = qMax(*naturalWidth, widthLayout.maximumWidth());
             }
+
+            bool wasInLayout = internalWidthUpdate;
+            internalWidthUpdate = true;
+            q->setImplicitWidth(*naturalWidth);
+            internalWidthUpdate = wasInLayout;
+
+            const qreal oldWidth = lineWidth;
+            lineWidth = q->widthValid() && q->width() > 0 ? q->width() : FLT_MAX;
+            if (lineWidth != oldWidth && (singlelineElide || multilineElide || canWrap || horizontalFit)) {
+                widthChanged = true;
+                continue;
+            }
         }
 
         // If the next needs to be elided and there's an abbreviated string available
@@ -911,32 +938,36 @@ QRectF QQuickTextPrivate::setupTextLayout(qreal *const naturalWidth)
         if (horizontalFit) {
             if (unelidedRect.width() > lineWidth || (!verticalFit && wrapped)) {
                 largeFont = scaledFontSize - 1;
-                scaledFontSize = (smallFont + largeFont) / 2;
                 if (smallFont > largeFont)
                     break;
+                scaledFontSize = (smallFont + largeFont) / 2;
+                if (pixelSize)
+                    scaledFont.setPixelSize(scaledFontSize);
+                else
+                    scaledFont.setPointSize(scaledFontSize);
                 continue;
             } else if (!verticalFit) {
                 smallFont = scaledFontSize;
-                scaledFontSize = (smallFont + largeFont + 1) / 2;
                 if (smallFont == largeFont)
                     break;
+                scaledFontSize = (smallFont + largeFont + 1) / 2;
             }
         }
 
         if (verticalFit) {
             if (truncateHeight || unelidedRect.height() > maxHeight) {
                 largeFont = scaledFontSize - 1;
-                scaledFontSize = (smallFont + largeFont + 1) / 2;
                 if (smallFont > largeFont)
                     break;
+                scaledFontSize = (smallFont + largeFont) / 2;
+
             } else {
                 smallFont = scaledFontSize;
-                scaledFontSize = (smallFont + largeFont + 1) / 2;
                 if (smallFont == largeFont)
                     break;
+                scaledFontSize = (smallFont + largeFont + 1) / 2;
             }
         }
-
     }
 
     if (eos != multilengthEos)
diff --git a/src/quick/items/qquicktextedit.cpp b/src/quick/items/qquicktextedit.cpp
index 79df5abd11..4fa5233b9a 100644
--- a/src/quick/items/qquicktextedit.cpp
+++ b/src/quick/items/qquicktextedit.cpp
@@ -1143,7 +1143,8 @@ void QQuickTextEdit::setInputMethodHints(Qt::InputMethodHints hints)
 void QQuickTextEdit::geometryChanged(const QRectF &newGeometry,
                                   const QRectF &oldGeometry)
 {
-    if (newGeometry.width() != oldGeometry.width())
+    Q_D(QQuickTextEdit);
+    if (newGeometry.width() != oldGeometry.width() && d->wrapMode != NoWrap && !d->inLayout)
         updateSize();
     QQuickImplicitSizeItem::geometryChanged(newGeometry, oldGeometry);
 }
@@ -1857,6 +1858,13 @@ void QQuickTextEdit::updateSize()
             if (d->requireImplicitWidth) {
                 d->document->setTextWidth(-1);
                 naturalWidth = d->document->idealWidth();
+
+                const bool wasInLayout = d->inLayout;
+                d->inLayout = true;
+                setImplicitWidth(naturalWidth);
+                d->inLayout = wasInLayout;
+                if (d->inLayout)    // probably the result of a binding loop, but by letting it
+                    return;         // get this far we'll get a warning to that effect.
             }
             if (d->document->textWidth() != width())
                 d->document->setTextWidth(width());
@@ -1888,11 +1896,11 @@ void QQuickTextEdit::updateSize()
             d->document->setTextWidth(newWidth); // ### Text does not align if width is not set (QTextDoc bug)
         // ### Setting the implicitWidth triggers another updateSize(), and unless there are bindings nothing has changed.
         qreal iWidth = -1;
-        if (!widthValid())
+        if (!widthValid() && !d->requireImplicitWidth)
             iWidth = newWidth;
-        else if (d->requireImplicitWidth)
-            iWidth = naturalWidth;
+
         qreal newHeight = d->document->isEmpty() ? fm.height() : d->document->size().height();
+
         if (iWidth > -1)
             setImplicitSize(iWidth, newHeight);
         else
diff --git a/src/quick/items/qquicktextedit_p_p.h b/src/quick/items/qquicktextedit_p_p.h
index 055b5c7929..f0a35d5266 100644
--- a/src/quick/items/qquicktextedit_p_p.h
+++ b/src/quick/items/qquicktextedit_p_p.h
@@ -78,7 +78,7 @@ public:
         , documentDirty(true), dirty(false), richText(false), cursorVisible(false)
         , focusOnPress(true), persistentSelection(false), requireImplicitWidth(false)
         , selectByMouse(false), canPaste(false), canPasteValid(false), hAlignImplicit(true)
-        , rightToLeftText(false), textCached(false)
+        , rightToLeftText(false), textCached(false), inLayout(false)
     {
     }
 
@@ -144,6 +144,7 @@ public:
     bool hAlignImplicit:1;
     bool rightToLeftText:1;
     bool textCached:1;
+    bool inLayout:1;
 };
 
 QT_END_NAMESPACE
diff --git a/src/quick/items/qquicktextinput.cpp b/src/quick/items/qquicktextinput.cpp
index c9b2e7b41e..7d7fe851b3 100644
--- a/src/quick/items/qquicktextinput.cpp
+++ b/src/quick/items/qquicktextinput.cpp
@@ -1604,9 +1604,11 @@ void QQuickTextInput::geometryChanged(const QRectF &newGeometry,
                                   const QRectF &oldGeometry)
 {
     Q_D(QQuickTextInput);
-    if (newGeometry.width() != oldGeometry.width())
-        d->updateLayout();
-    updateCursorRectangle();
+    if (!d->inLayout) {
+        if (newGeometry.width() != oldGeometry.width() && d->wrapMode != NoWrap)
+            d->updateLayout();
+        updateCursorRectangle();
+    }
     QQuickImplicitSizeItem::geometryChanged(newGeometry, oldGeometry);
 }
 
@@ -2699,6 +2701,38 @@ void QQuickTextInputPrivate::updateDisplayText(bool forceUpdate)
     }
 }
 
+qreal QQuickTextInputPrivate::getImplicitWidth() const
+{
+    Q_Q(const QQuickTextInput);
+    if (!requireImplicitWidth) {
+        QQuickTextInputPrivate *d = const_cast<QQuickTextInputPrivate *>(this);
+        d->requireImplicitWidth = true;
+
+        if (q->isComponentComplete()) {
+            // One time cost, only incurred if implicitWidth is first requested after
+            // componentComplete.
+            QTextLayout layout(m_text);
+
+            QTextOption option = m_textLayout.textOption();
+            option.setTextDirection(m_layoutDirection);
+            option.setFlags(QTextOption::IncludeTrailingSpaces);
+            option.setWrapMode(QTextOption::WrapMode(wrapMode));
+            option.setAlignment(Qt::Alignment(q->effectiveHAlign()));
+            layout.setTextOption(option);
+            layout.setFont(font);
+            layout.setPreeditArea(m_textLayout.preeditAreaPosition(), m_textLayout.preeditAreaText());
+            layout.beginLayout();
+
+            QTextLine line = layout.createLine();
+            line.setLineWidth(INT_MAX);
+            d->implicitWidth = qCeil(line.naturalTextWidth());
+
+            layout.endLayout();
+        }
+    }
+    return implicitWidth;
+}
+
 void QQuickTextInputPrivate::updateLayout()
 {
     Q_Q(QQuickTextInput);
@@ -2718,6 +2752,15 @@ void QQuickTextInputPrivate::updateLayout()
     boundingRect = QRectF();
     m_textLayout.beginLayout();
     QTextLine line = m_textLayout.createLine();
+    if (requireImplicitWidth) {
+        line.setLineWidth(INT_MAX);
+        const bool wasInLayout = inLayout;
+        inLayout = true;
+        q->setImplicitWidth(qCeil(line.naturalTextWidth()));
+        inLayout = wasInLayout;
+        if (inLayout)       // probably the result of a binding loop, but by letting it
+            return;         // get this far we'll get a warning to that effect.
+    }
     qreal lineWidth = q->widthValid() ? q->width() : INT_MAX;
     qreal height = 0;
     do {
@@ -2737,7 +2780,11 @@ void QQuickTextInputPrivate::updateLayout()
 
     updateType = UpdatePaintNode;
     q->update();
-    q->setImplicitSize(boundingRect.width(), boundingRect.height());
+
+    if (!requireImplicitWidth && !q->widthValid())
+        q->setImplicitSize(qCeil(boundingRect.width()), qCeil(boundingRect.height()));
+    else
+        q->setImplicitHeight(qCeil(boundingRect.height()));
 
     if (previousRect != boundingRect)
         emit q->contentSizeChanged();
diff --git a/src/quick/items/qquicktextinput_p_p.h b/src/quick/items/qquicktextinput_p_p.h
index bb00600661..165155acd0 100644
--- a/src/quick/items/qquicktextinput_p_p.h
+++ b/src/quick/items/qquicktextinput_p_p.h
@@ -125,6 +125,8 @@ public:
         , m_acceptableInput(1)
         , m_blinkStatus(0)
         , m_passwordEchoEditing(false)
+        , inLayout(false)
+        , requireImplicitWidth(false)
     {
     }
 
@@ -256,7 +258,8 @@ public:
     bool m_acceptableInput : 1;
     bool m_blinkStatus : 1;
     bool m_passwordEchoEditing : 1;
-
+    bool inLayout:1;
+    bool requireImplicitWidth:1;
 
     static inline QQuickTextInputPrivate *get(QQuickTextInput *t) {
         return t->d_func();
@@ -404,6 +407,8 @@ public:
 
     void updateLayout();
 
+    qreal getImplicitWidth() const;
+
 private:
     void removeSelectedText();
     void internalSetText(const QString &txt, int pos = -1, bool edited = true);